A guide for using NIH Image J for single slice cross-sectional area and composition analysis of the thigh from computed tomography.

Reports using computed tomography (CT) to estimate thigh skeletal muscle cross-sectional area and mean muscle attenuation are often difficult to evaluate due to inconsistent methods of quantification and/or poorly described analysis methods. This CT tutorial provides step-by-step instructions in using free, NIH Image J software to quantify both muscle size and composition in the mid-thigh, which was validated against a robust commercially available software, SliceOmatic. CT scans of the mid-thigh were analyzed from 101 healthy individuals aged 65 and older. Mean cross-sectional area and mean attenuation values are presented across seven defined Hounsfield unit (HU) ranges along with the percent contribution of each region to the total mid-thigh area. Inter-software correlation coefficients ranged from R2 = 0.92-0.99 for all specific area comparisons measured using the Image J method compared to SliceOmatic. We recommend reporting individual HU ranges for all areas measured. Although HU range 0-100 includes the majority of skeletal muscle area, HU range -29 to 150 appears to be the most inclusive for quantifying total thigh muscle. Reporting all HU ranges is necessary to determine the relative contribution of each, as they may be differentially affected by age, obesity, disease, and exercise. This standardized operating procedure will facilitate consistency among investigators reporting computed tomography characteristics of the thigh on single slice images. Trial Registration: ClinicalTrials.gov NCT02308228.

Tutorial for using SliceOmatic to calculate thigh area and composition from computed tomography images from older adults.

OBJECTIVE: Area of muscle, fat, and bone is often measured in thigh CT scans when tissue composition is a key outcome. SliceOmatic software is commonly referenced for such analysis but published methods may be insufficient for new users. Thus, a quick start guide to calculating thigh composition using SliceOmatic has been developed. METHODS: CT images of the thigh were collected from older (69 ± 4 yrs, N = 24) adults before and after 12-weeks of resistance training. SliceOmatic was used to segment images into seven density regions encompassing fat, muscle, and bone from -190 to +2000 Hounsfield Units [HU]. The relative contributions to thigh area and the effects of tissue density overlap for skin and marrow with muscle and fat were determined. RESULTS: The largest contributors to the thigh were normal fat (-190 to -30 HU, 29.1 ± 7.4%) and muscle (35 to 100 HU, 48.9 ± 8.2%) while the smallest were high density (101 to 150 HU, 0.79 ± 0.50%) and very high density muscle (151 to 200 HU, 0.07 ± 0.02%). Training significantly (P<0.05) increased area for muscle in the very low (-29 to -1 HU, 5.5 ± 7.9%), low (0 to 34 HU, 9.6 ± 16.8%), normal (35 to 100 HU, 4.2 ± 7.9%), and high (100 to 150 HU, 70.9 ± 80.6%) density ranges for muscle. Normal fat, very high density muscle and bone did not change (P>0.05). Contributions to area were altered by ~1% or less and the results of training were not affected by accounting for skin and marrow. CONCLUSIONS: When using SliceOmatic to calculate thigh composition, accounting for skin and marrow may not be necessary. We recommend defining muscle as -29 to +200 HU but that smaller ranges (e.g. low density muscle, 0 to 34 HU) can easily be examined for relationships with the health condition and intervention of interest. TRIAL REGISTRATION: Clinicaltrials.gov NCT02261961.

Imaging algorithms for evaluating suspected rotator cuff disease: Society of Radiologists in Ultrasound consensus conference statement.

The Society of Radiologists in Ultrasound convened a panel of specialists from a variety of medical disciplines to reach a consensus about the recommended imaging evaluation of painful shoulders with clinically suspected rotator cuff disease. The panel met in Chicago, Ill, on October 18 and 19, 2011, and created this consensus statement regarding the roles of radiography, ultrasonography (US), computed tomography (CT), CT arthrography, magnetic resonance (MR) imaging, and MR arthrography. The consensus panel consisted of two co-moderators, a facilitator, a statistician and health care economist, and 10 physicians who have specialty expertise in shoulder pain evaluation and/or treatment. Of the 13 physicians on the panel, nine were radiologists who were chosen to represent a broad range of skill sets in diagnostic imaging, different practice types (private and academic), and different geographical regions of the United States. Five of the radiologists routinely performed musculoskeletal US as part of their practice and four did not. There was also one representative from each of the following clinical specialties: rheumatology, physical medicine and rehabilitation, orthopedic surgery, and nonoperative sports medicine. The goal of this conference was to construct several algorithms with which to guide the imaging evaluation of suspected rotator cuff disease in patients with a native rotator cuff, patients with a repaired rotator cuff, and patients who have undergone shoulder replacement. The panel hopes that these recommendations will lead to greater uniformity in rotator cuff imaging and more cost-effective care for patients suspected of having rotator cuff abnormality.

Clavicle morphometry revisited: a 3-dimensional study with relevance to operative fixation.

BACKGROUND: The advocacy for operative fixation of midshaft clavicle fractures has prompted a reemergence of interest in clavicle anatomy. Three-dimensional (3D) anatomical studies provide more information than 2-dimensional studies, but are currently rare. MATERIAL AND METHODS: Twenty-five skeletonized clavicles were digitized using a laser scanner. Three-dimensional computer software was used to analyze the data. Clavicles were divided into medial, middle, and lateral segments based on the medial and lateral apices of curvature and their lengths and midpoint cortical diameter measured. The angles of medial and lateral curvatures were measured in standardized axial and coronal planes. The medial and lateral curvatures were fitted with circles and the radii of curvature measured. Correlations between the intrinsic dimensions of the clavicle were assessed. RESULTS: The mean length was 136.7 mm. The medial, middle, and lateral segments had mean lengths of 48, 56, and 32.7 mm, respectively. In the axial plane, the mean medial and lateral angles were 149.5° and 145.8°, respectively. In the coronal plane, the mean medial and lateral angles were 178.2° and 174.2°, respectively. The mean midpoint cortical diameter was 10.9 mm. The mean medial and lateral radii of curvature were 66.4 and 33.5 mm, respectively. The length and cortical diameter and length and medial radius of curvature were found to positively correlate, R(2) = .355 and .184, respectively. CONCLUSION: Using standardized measurements, we were able to accurately characterize the dimensions of the clavicle. We found that the length of the clavicle correlates with the midpoint cortical diameter and with the radius of medial curvature.

ACR appropriateness criteria(®) acute trauma to the knee.

There are more than 1 million visits to the ER annually in the United States for acute knee trauma. Many of these are twisting injuries in young patients who can walk and bear weight, and emergent radiography is not required. Several clinical decision rules have been devised that can considerably reduce the number of radiographic studies ordered without missing a clinically significant fracture. Although fractures are seen on only 5% of emergency department knee radiographs, 86% of knee fractures result from blunt trauma. In patients with falls or twisting injuries who have focal tenderness, effusion, or inability to bear weight, radiography should be the first imaging study performed. If radiography shows no fracture, MRI is best for evaluating for a suspected meniscal or ligament tear or patellar dislocation. Patients with knee dislocation should undergo radiography and MRI, as well as fluoroscopic angiography, CT angiography, or MR angiography. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR Appropriateness Criteria® on acute shoulder pain.

The shoulder joint is a complex array of muscles, tendons, and capsuloligamentous structures that has the greatest freedom of motion of any joint in the body. Acute (<2 weeks) shoulder pain can be attributable to structures related to the glenohumeral articulation and joint capsule, rotator cuff, acromioclavicular joint, and scapula. The foundation for investigation of acute shoulder pain is radiography. Magnetic resonance imaging is the procedure of choice for the evaluation of occult fractures and the shoulder soft tissues. Ultrasound, with appropriate local expertise, is an excellent evaluation of the rotator cuff, long head of the biceps tendon, and interventional procedures. Fluoroscopy is an excellent modality to guide interventional procedures. Computed tomography is an excellent modality for characterizing complex shoulder fractures. Computed tomographic arthrography or fluoroscopic arthrography may be alternatives in patients for whom MR arthrography is contraindicated. A multimodal approach may be required to accurately assess shoulder pathology. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR appropriateness criteria on metastatic bone disease.

Appropriate imaging modalities for screening, staging, and surveillance of patients with suspected and documented metastatic disease to bone include (99m)Tc bone scanning, MRI, CT, radiography, and 2-[(18)F]fluoro-2-deoxyglucose-PET. Clinical scenarios reviewed include asymptomatic stage 1 breast carcinoma, symptomatic stage 2 breast carcinoma, abnormal bone scan results with breast carcinoma, pathologic fracture with known metastatic breast carcinoma, asymptomatic well-differentiated and poorly differentiated prostate carcinoma, vertebral fracture with history of malignancy, non-small-cell lung carcinoma staging, symptomatic multiple myeloma, osteosarcoma staging and surveillance, and suspected bone metastasis in a pregnant patient. No single imaging modality is consistently best for the assessment of metastatic bone disease across all tumor types and clinical situations. In some cases, no imaging is indicated. The recommendations contained herein are the result of evidence-based consensus by the ACR Appropriateness Criteria((R)) Expert Panel on Musculoskeletal Radiology.

ACR Appropriateness Criteria on suspected osteomyelitis in patients with diabetes mellitus.

Imaging of the diabetic foot is among the most challenging areas of radiology. The authors present a consensus of the suggested tests in several clinical scenarios, such as early neuropathy, soft-tissue swelling, skin ulcer, and suspected osteomyelitis. In most of these situations, magnetic resonance imaging (MRI) with or without contrast is the examination of choice. Most other imaging tests have complementary roles. For soft-tissue swelling or an ulcer, radiography and MRI with or without contrast are suggested. Bone scintigraphy with white blood cell scanning is used when MRI is contraindicated. In patients with diabetes without ulcers, radiography and MRI with or without contrast are suggested; bone scanning may be used when MRI is contraindicated.

Percutaneous cholecystostomy catheter removal and incidence of clinically significant bile leaks: a clinical approach to catheter management.

OBJECTIVE: We sought to determine the incidence of bile leaks upon removal of small-bore percutaneous cholecystostomy catheters and to evaluate clinical and imaging guidelines to ensure safe catheter removal. MATERIALS AND METHODS: A retrospective evaluation of all gallbladder drainages performed over a 5-year period revealed 163 patients (range, 7-98 years) who underwent percutaneous cholecystostomy catheter placement. Medical records and imaging studies were reviewed to assess the events at catheter removal (e.g., inadvertent removal, controlled removal with cholangiography without tract imaging, or controlled removal with cholangiography with tract imaging) and the incidence of major and minor bile leaks. RESULTS: The events at catheter removal were assessed in 66 patients. Group 1 was 45 patients whose catheters were removed after a minimum of approximately 3 weeks with a cholangiogram that established cystic and common duct patency and no imaging of the tract. Catheters were not removed until the patient recovered from acute illnesses that contributed to acalculous cholecystitis. Group 2 was 11 patients managed similarly to group 1 except that tract imaging was performed at catheter removal. Group 3 was 10 patients whose tubes came out inadvertently without cholangiogram or tract imaging. Two major (group 2 and group 3) and two minor (group 2) bile leaks occurred. No bile leaks occurred in group 1 (p = 0.006). CONCLUSION: Major bile leaks occurred in 3% of patients, and minor leaks occurred with equal frequency. Tract imaging may not be necessary in patients with small-bore gallbladder catheters who have recovered from critical illness, show patent cystic and common ducts, and have had catheters for 3-6 weeks.